What Are The Side Effects Of Cyclafem 1/35?

I had my last period start December 28th, and it was very short. I was on the pill Necon 1/35 and switched from Necon to Cyclafem 1/35 on the Sunday I would usually start a new pack.I had sex in-between that period where I was on my inactive pills right before my period started. On Wednesday, I noticed nausea, and the symptoms kept on getting worse throughout the week. By the 12th of January I had dizziness, and extreme nausea/ vomiting. I took a pregnancy test a week before my period (the 21st) and got a faint positive and around 6 days before my period was supposed to come I had a single brown chunk of discharge , no blood, just clear mucus. I stopped taking the pill on Friday because I assumed that my symptoms were because of the pill and I was unable to hold any food down. Today I experienced major migraines and cramping and i started bleeding, however the blood was completely black and the texture of tar. What could be going on? I am worried about pregnancy or some other issue, and I am unable to test again until later. Please help!!